Meta Keywords have no importance now. Google has devalued it in the year 2009. This is due to the reason people started stuffing in that tag. They fill hundreds of keywords in the meta keywords tag. That's why Google devalued it.

Google devalued meta keywords long time ago. Right now there is no importance for using meta keywords on a website, we are using it just for the sake of what keywords we are targeting for particular page, that's it.

Meta keywords are not significant for Google but for other look for engines it does. Yahoo, bang and other lesser search robots do concerned concerning these keywords. They assist them connect the indexed content to the correct keywords, at least in the initial phase. So, if you desire to get rankings only in google and not in other look for engine, take away the Meta keywords.

Google doesn't care much about meta keywords now.However, using them won't impact rankings significantly anyways, use it if you want to anyways.I couldn't say anything about other search engines like bing,yahoo,etc because I hear the meta keywords do have importance there.

Google dose not look at Meta-Keywords (as was clearly stated by Matt Cutts). Other SE and information gathering tools might use Keywords Meta. It dosen`t "hurts" you to have them but don`t waste time on them.

I would suggest a long "all in one" keyword list that will be true for all pages on site.